Photographic material containing nitro compounds for the silver dyestuff bleaching process

ABSTRACT

AROMATIC OR HETEROCYCLIC NITRO COMPOUNDS AS OXIDIZING AGENTS FOR THE REDUCED DYESTUFF BLEACHING CATALYST IN PHOTOGRAPHIC MATERIAL FOR THE SILVER DYESTUFF BLEACHING PROCESS.

United States Patent 3,782,948 PHOTOGRAPHIC MATERIAL CONTAINING NITROCOMPOUNDS FOR THE SILVER DYESTUFF BLEACHING PROCESS Alfred Froehlich,Marly-le-Grand, and Alfred Oetiker v, :lmdHeinrich,Schaller, Fribonrg,Switzerland, assignors to Ciba-Geigy AG, Basel, Switzerland No Drawing.Continuation-impart of abandoned applica- Ktion' Ser. No. 812,860, Apr.2, 1969. This application Jan; 13, 1972; Ser. No. 217,654

priority, application Switzerland, Apr. 9, 1968, 5,236/68 a Int. Cl.G03c 1/76 U.S.Cl. 96-73- 11 Claims ABSTRACT OF THE DISCLOSURE Aromaticor heterocyclic nitro compounds as oxidizing agents for thereduceddyestuffbleaching catalyst in photographic. material for thesilver dyestufi bleaching process.

Thisapplication is a continuation-inpart of our copending applicationSer. No. 812,860, filed Apr. 2, 1969, now abandoned. The presentinvention provides a photographic material for the s'iIver-dyestuffbleaching process said material consisting of different layers andcontaining in at least one silver halide layer an azo dye that can bebleached by silver which material contains in at least one of saidlayers a colorless or faintly colored nitro compound of the formula inwhich A represents an aromatic or heterocyclic residue consisting of oneor two rings each containing 5 or 6 ring members; B represents anorganic residue containing at least 8 members; D and E each representsan acid water-solubilizing group; m, n and p each represents 1, 2 or 3,and q and r each represents an integer of at least one. The residue Bis, for example, an at least 8-membered carbon chain which may containhetero atoms.

Particularly valuable nitro compounds are those of the in which Arepresents a benzene, naphthalene, diphenyl, pyridine, quinoline orphenylpyrazolone residue; 13,, represents an organic residue whichcontains one or two aliphatic chains consisting of carbon atoms and, ifdesired, oxygen and/or nitrogen atoms, these chains containing a totalof at least twelve members; D and E each represents a sulphonic orcarboxylic acid group; 11,, m p and r each represents 1 or 2, and q ==1,2 or 3.

3,782,948 Patented Jan. 1, 1974 ice Expressed in a simplified manner,the nitro compounds of Formula 3 constitute compounds of one of thefollowing 3 types:

Particularly suitable are nitro compounds of the in which B D E m n p q,and r have the above meanings and A represents a benzene or naphthaleneresidue.

Of special value are nitro compounds of the formula in which A D E m 11p q and r have the above meanings and B represents a residue whichcontains at least one aliphatic chain consisting of carbon atoms and, ifdesired, oxygen and/or nitrogen atoms, of at least twelve members inall, which residue is linked with the residue A directly or through anNR-CO-, ---CONR---, O- or NR-- bridge, where R represents a hydrogenatom or a lower alkyl group.

Among these nitro compounds those of formula (\NOm (m -l] (l -n+1 arepreferred; in this formula A D E m n p q and r have the above meaningsand B represents a residue which contains at least one aliphatic chainconsisting of carbon atoms and, if desired, oxygen and/or nitrogenatoms, of at least twelve members, which residue is linked with Adirectly or through an 0 or an NRC-0- bridge, where R represents ahydrogen atom or a lower alkyl group.

In the first place nitro compounds of the formula ilp-a (\NOm (a ea -n+1(m -1) (r-ll +1 in which A2, B4, D1, E1, "'11, n p q] and r1 have theabove meanings, are preferably used.

Among the nitro compounds of the Formula 7 those are especially valuablewhich correspond to the formula NH-C o-o O2N D1 in which G represents aresidue of the formula xHZxft or C H COO'H (where x is a digit of from11 to 17 and y a digit of from 14 to 20) and D represents a sulphonic orcarboxylic acid group.

The compounds of the Formulae 1 to 8 can be readily manufactured byknown methods, for example by reacting an acid chloride, for instancestearoyl chloride, lauroyl chloride, sebacinoyl chloride, abiethinoylchlo ride, or an acid anhydride for instance dodecenyl'suo cinicanhydride, with the corresponding aminonitro compounds, or by reactingaromatic nitro compounds containing a replaceable halogen atom, forexample 4-nitrochlorobenzene-Z-sulphonic acid, with adifiusioninhibiting amine or enol, for example 1,12-diaminm dodecane,N-methyloctadecylamine, pentaor tetra-ethyleneglycol orpolyethylene-imine, or by reacting aromatic nitro-isocyanates, forexample 3-nitro-phenylisocyanate or 3nitrophenyl-sulphonylisocyanate,with a dilfusionresistant amine or enol. These processes are merelygiven by way of examples and certainly do not exhaust all the possiblemethods of manufacture.

The residue A in the Formula 1 preferably represents an aromatic residueconsisting of one or two rings, for example a benzene or naphthaleneresidue or a heterocyclic residue consisting of one or two rings, forexample a pyridine or quinoline ring; or A may also represent anaromatic-heterocyclic system, for example a phenylpyrazolone residue.The residue A contains one or two nitro groups and may also besubstituted by one or two acid water-solubilizing groups, for examplesulphonic or carboxylic acid groups. Furthermore, the residue A may belinked with the residue B either directly or through a bridge member.

B as diffusion-inhibiting group may be bound to group A directly orthrough a bridge member, e.g. S,

where R is hydrogen or an alkyl group having at most 5 carbon atoms.

As diffusion-inhibiting groups B are suitable, for instance, linear orbranched, saturated or unsaturated substituted or unsubstitutedhydrocarbon radicals which when substituted contain (a) nitrogen, oxygenor nitrogen and oxygen atoms, as substituents or chain members, (b)carbocyclic nuclei and (c) carbocyclic nuclei and nitrogen, oxygen ornitrogen and oxygen as substituents or chain members, saiddiffusion-inhibiting group containing at least 8 members. The actualdifiusion-inhibiting residue within the residue B may also be linkedwith an aromatic or heterocyclic ring, for example with a. benzene ring.This ring may, if desired, contain several such diifusion-inhibitingresidues, in which case the residue B is advantageously linked with A bya bond starting from the ring.

Diffusion-inhibiting residues which represent the residue B itself oronly a part thereof are, for example, alkyl, e.g. dodecyl, alkylamino,e.g. dodecylamino, alkanoyl, e.g. pentanoyl, capryl, lauroyl, stearoyl;phenylcarbamoylalkylenecarbonyl; alkylphenoxymethylene;alkanoylaminophenylcarbamoylanilide, alkanoylphenylcarbamoyl;phenoxypolyethyleneoxyalkylene; alkylpyrazolone; N-alkylated-aminophenyl; aliphatic carbocyclic having up to 19 carbonatoms e.g. 1methyl-7-isopropylphenanthr- 1-yl; benzamidodiphenylaminooptionally substituted in the diphenyl moiety by lower alkoxy,phenylcarbamoyloxy-polyethyleneoxy-carbonyl and anilinoalkylene havingup to carbon atoms in the alkylene moiety.

The acid water-solubilizing groups D and E are linked with A or B; it ispossible that both A and B, or only A, or only B or neither A nor Bcontain such groups. D and E preferably represent sulphonic orcanboxylic acid groups. An acid group linked with B is formed, forexample, by using an alkylene-substituted succinic anhydride or asulphonatable unsaturated aliphatic compound, for example oleic acid, asacylating agent for A. When the residue B represents, for example, atetraor pentaethylene glycol residue or a polyvinyl alcohol residue, theintroduction of acid water-solubilizing groups into the molecule of thenitro compound may be dispensed with without sacrificing the solubilityin water. The compounds of the Formula 1 may also be insoluble in water;such nitro compounds may also be soluble in a sparingly volatile organicsolvent, for example in tricresyl phosphate or dibutyl phthalate.

The atomic grouping of the formula (\Nom t in which A, D, n, p and rhave the above meanings may appear in the molecule once or twice,depending on the number of the bond-forming groups in B. For example,tetraor pentaethylene glycol combine through their hydroxyl groups withtwo residues of the Formula 9, as do diamines, for examplediaminodecane, or dicarboxylic acids, for example sebacic acid, whilepolyvalent residues B, for example polyvinyl alcohol, maleic anhydridecopolymers or carbohydrates are capable of combining with severalresidues of the Formula 9; in. the case of the maleic anhydridecopolymers the number of the liberated canboxyl groups in the ester oramide-like compound comprising the residue of the Formula 9 depends onthe polymer and on the degree of conversion reached.

The residue of the Formula 9 may also be linked With thediffusion-inhibiting residue through so-called reactive compounds, forexample cyanuric chloride, dichloropyrimidine, B-chloropropionylchloride, dichloroquinoxaline carboxylic acid chloride or the like.Apart-from the difiusion-inhibiting residues already mentionedwatersoluble polymers miscible with gelatin are suitable above all, orunder certain conditions even gelatin itself.

A few examples of nitro compounds of Formula 1 are the followingcompounds of the Formulae I to XXXI:

His

02N- NEG-CO-CnHu (II) can OzN- NIH-C OCHgC HC 15H OaH (III) -NH-CO-CHz-C HC12H28 O OH zN (IV) 10 on p p o aNO-NH-C Q-CH2 0 131-0 n coon vNH-CO-CHz-CH-OrzE: 3 0 OH V om NHCO--CHz-CH-Cr2Hz;

l to...-

(VI) SOaH (XXXI) C 11 Specially suitable nitro compounds are those ofthe Formulae I, XXIX, XXX and XXXI.

In addition to these monomers, polymers may also be mentioned, forexample the reaction product of polyvinyl alcohol with3-nitrophenylisocyanate or the reaction product of a vinylalcohol/maleic anhydride copolymer with 1-amino-3-nitrobenzene.

The nitro compounds of the Formula 1 are substantially colorless and asa rue soluble as such or in the form of their alkali metal salts inwater or in a mixture of water and an organic solvent, preferablymethanol. When introduced into gelatine, they dry together with it andare then glass clear, even when they are dispersed in the gelatine.Water-insoluble nitro compounds may be dissolved in a sparingly volatileorganic solvent and then finely dispersed in the gelatine.

In a multi-layer material the nitro compounds of Formula 1 may be addedto all the layers or only to some of the emulsion, dye, emulsion dye,intermediate or auxiliary layers according to the desired effect. In thecase of mixed grain emulsions the nitro compounds may be introduced intothe disperse phase and/or the binder layer which serves as a matrix. Theterm intermediate layers comprises especially the separating layers,while the auxiliary layers are lubricating layers, protective layers,filter layers, antihalation layers, or coatings, substrations and barytalayers.

It is a special advantage of the compounds of the Formula I that owingto their diffusion stability they remain in the layers to which theyhave been added and neither migrate into the baths nor exert anundesirable influence on adjacent layers. Their diffusion stability alsoprevents migration within the layer so that the nitro compound can onlyact in the area where it is present.

When the nitro compounds of the Formula 1 are used in the intermediatelayers, the application of a bleaching catalyst improves the quality ofthe image. As is known, the bleaching catalysts used in a bleachingprocess with metallic silver are reduced to hydro compounds which thenundergo reoxidation and cause the bleaching of the dye. The reducedform, provided it does not act immediately in the bleaching process,migrates into the adjacent layers where it produces an undesired andharmful bleaching of the image dye. The nitro compounds in theintermediate layers prevent this harmful effect by oxidizing the reducedcatalyst migrating from the layer.

Owing to their diffusion stability these nitro compounds can be added indifferent concentrations to the individual layers of a multi-layermaterial, especially to those which contain the image dye, with a viewto influencing the sensitometric properties of the image-forming layersindividually and thereby improving the physical properties of the imagein the multi-layers.

The nitro compounds of the Formula 1, especially those which contain twonitro groups (m=2) in the residue A, are specially suitable for thispurpose because of their high oxidation potential. Since one nitro groupis equivalent to six hydrogen atoms, a smaller quantity of the nitrocompound of the Formula 1 will be needed than, for example, of aquinone, a nitroso compound or an azo dye, which correspond to two, orat most to four hydrogen atoms. For example:

The absence of color in many of the nitro compounds of Formula 1 isespecially important for use in opaque color prints in viewing which thedye is particularly sensitive even to a slight yellow cast.

For example, a 0.02-molar aqueous quinone solution has at 420 nm. anabsorption maximum of 0.76 density, whereas the compound of the FormulaI, that is 2-stear0ylamino-6-nitrotoluene-4-sulphonic acid, in the sameconcentration shows no absorption in the visible region. In contrast toquinones and nitroso compounds these nitro compounds are stable and arenot affected by the action of light. For example, the initially paleyellow solution of quinone in gelatine, prepared by adding 20 ml. of amethanolic 0.1-molar solution to ml. of 3.75% gelatine solution, turnsbrownish red when exposed to daylight for a short time, whereas asimilarly prepared solution of the compound of the Formula I remainscolorless. When 10 ml. each of these gelatine solutions are cast over aglass plate measuring 13 x 18 cm., the compound of the Formula 1 forms acolorless layer, as against a reddish layer with quinone, which does not.lose its color even when rinsed in water. In contrast to the quinonesthe nitro compounds do not react with the developers under the usualdeveloping conditions, for example with hydroquinone. I

The diflusion-resistant and soluble nitro compounds are easy and cheapto manufacture.

The nitro compounds of the Formula 1 offer special advantages when usedas additives to separating, filter or antihalation layers that containcolloidal silver or a fogged silver halide emulsion. 1

In the past such layers could not be used in materials for the silverdye bleaching process because during the bleaching process silverconverts the dye bleaching catalyst into a reduced form which thenmigrates into the adjacent layers where it bleaches the dyes inunexposed, that is silver-free areas. When one of the nitro compounds ofthe Formula 1 is added to the filter or antihalation layers, and thecolloidal silver or the silver formed during the developing from thepre-exposed silver halide is bleached, either the catalyst is notreduced or the activated catalyst produced is immediately reoxidized andcannot produce any undesirable dye bleaching in the adjacent layers.

It is not a disadvantage when an excess of a nitro compound of Formula 1is incorporated with the layers, especially the auxiliary layers. t

By using the nitro compounds of the Formula 1 in protective or coverlayers the enrichment of the reduced form of the dye bleaching catalystin the corresponding bath can be prevented, whereas otherwise-thecatalyst concentration is diflicult to keep constant.

When the nitro compounds of the Formula'l are added to dyed layers, thenitro compounds compete with the dye during the bleaching process,whereby in general a flatter gradation in the dyed layer is produced.

. 9 .MANUFACTURING INSTRUCTIONS :10 grams of2-amino-6-nitrotoluene-4-sulphonic acid are dissolved in 100 ml. ofpyridine and 12.5 g. of stearoyl chloride rare stirred in di opwise atthe boil; the dropwise addition of stearo'yl chloride is continued untilno more aminotnitrotoluene sulphonic acid can be identified by adiazotization and coupling test. The pyridine is then distilled on asteam bath under vacuum and the residue is triturated with 100 ml. ofacetone, suction filtered and the residue washed with acetone. Afterrecrystallization from alcohol with 1 g. of active carbon 18 g. ofZ-nitro- 6-stearoylaminotoluene-4-sulphonic acid are obtained of theFormula I, melting at 193 to 199 C.

24.8 g. of l-nitro-methoxy 4 aminobenzene-6-sulphonic acid are suspendedin 1150 ml. of pyridine and 35 ml. of stearoyl chloride are slowlystirred in at the boil. The addition of stearoyl chloride is continueduntil free amine can no longer be identified by a diazotization andcoupling reaction. The pyridine is distilled under vacuum on a steambath and the residue is boiled with 300 ml. of acetone. It dissolvescompletely. Then 10 g. of active carbon are added and the batch issuction filtered hot and the mother liquor kept for 3 hours at -10 C. Itis again suction filtered and washed three times with 20 ml. of acetonecooled to C. on each occasion. After recrystallization from alcohol 39g. of colorless crystals are obtained melting at 171 C., which consistof the pyridine salt of1-methoxy-3-nitro-6-stearoylaminobenzene-4sulphonic acid of the FormulaXXIX.

216 g. of sodium Z-chloro-S-nitrobenzene sulphonate are dissolved in 520ml. of water, then 226 g. of methyloctadecylamine, 1200 mlLofisopropanol and 100 g. of

sodium bicarbonate are added and the whole is boiled for of glacialacetic acid and 55 ml. of water are refluxed and stirred for 6 hours,mixed with 4000 ml. of alcohol and 300 g. of finely powdered-nitro-2-methyl-octadecylaminobenzene sulphonic acid are introducedwithin 2 hours. The batch is boiled for another 24 hours and thenpotassium carbonate is added until an alkaline reaction to phenolphthalein has been attained, suction filtered hot and the residue washedwith 2000 ml. of boiling ethanol on each occasion. After cooling to roomtemperature the batch is suction filtered and the residue washed with300 m1. of ethanol and thoroughly pressed. The product is taken off thesuction filter without drying, dissolved in 150 ml. of glacial aceticacid, mixed with 30 g. of carbon, heated to theboil and suction filteredhot. The filtrate is mixed with 1000 ml. of water at the boil and thencooled to C.; the'precipitated crystals are suctionfilteredand'washedwith 1000 ml. of water. Another recrystallizationfrom1000 ml. of ethanol yields 200 g. of colorless crystals of4-methyl-octadecylamino-3-aminobenzene sulphonieacidmelting at 181 C. 25g. of this substance i11-150 ml.;of diethylaniline are heated to 100 Cand then mixed with 15 g. of 3,5-dinitrobenzoyl chloride. Moredinitrobenzoyl chloride is added until no more amine can be identifiedin the reaction mixture by diazotization. The reaction solution isstirred into 100 ml. of ether. The productyis at firstsmeary, but itcrystallizes 10 on prolonged standing. It is suction filtered, rinsedwith 100 ml. of ether and the residue is recrystallized from 1000 ml. ofmethanol. Yield: 20 g. of colorless powder melting at 150 C.

15 g. of this substance are suspended in 100 ml. of water at C. andmixed with 22 ml. of 2 N sodium carbonate solution. The clear solutionobtained is mixed at 60 C. with 20 ml. of 2 N sodium carbonate solution,whereupon the sodium salt is obtained as a yellow powder, which iscooled to 5 C., suction filtered and the residue rinsed with 500 ml. ofice water. Yield: 12 g. of the compound of the Formula XXX. The compoundof the Formula XXXiI is obtained in a similar manner.

Example 1 Two glass plates A and B, each measuring 13 x 18 cm., arecoated with a dye gelatine solution of the following composition: 3.3ml. of 6% gelatine solution, 2.0 ml. of 1,3-dichlorotriazine 5aminobenzene-4-sulphonic acid (1% solution), 0.5 ml. of a 1% solution ofthe dye of the formula @011 S OaH 4.2 ml. of water.

Plate A is coated with a solution of 5.0 ml. of 10% gelatin, 1.0 ml. of1% colloidal silver solution, 5.0 ml. of water and 2.0 ml. of1,3-dichlorotriazine-S-aminobenzene-4'-sulphonic acid (1% solution) andplate B with a solution at 5.0 ml. of 10% gelatin, 1.0 ml. of colloidalsilver solution (1% 5 .0 m1. of water, 0.125 g. of Z-nitro-6-stearoylaminotoluene-4-sulphonic acid, 2.0 m1. of 1,3-dichlorotriazine-S-aminobenzene-4'-sulphonic acid (1% Each plate A and Bis halved so that 4 plates, A A B and B are obtained.

From plates A and E the metallic silver is oxidized with the followingbleaching bath: 150 ml. of 37% hydrochloric acid, 25 g. of coppersulphate, 30 g. of potassium bromide, made up with water to 1 litre.

The plates A and B are subjected to the usual dye bleaching process asfollows:

They are immersed for 1 minute in a dye bleaching bath composed of: ml.of 37% hydrochloric acid, g. of potassium bromide, 8 g. of thiourea, 1ml. of 2,5-dimethylpyrazine, made up with water to 1 litre, then rinsedin water for 2 minutes, fixed in a solution of 150 g. of sodiumthiosulphate, 15 g. of sodium sulphite, 13.5 ml. of 100% acetic acid, 15g. of sodium metaborate and 15 g. of potassium aluminium sulphate, madeup with water to 1 litre, and then rinsed in water for 10 minutes.

The transparency of the residual magenta layer is measured with aspectrophotometer. The resulting values Example 2 As described inExample 1 a 7% gelatin solution is mixed at 40 C. with a solution of acyan image dye of the formula QC O-HN-Q and the usual casting additivesfor example a wetting agent, hardener and glycerine. By adding therequisite quantity of water the viscosity is then adjusted to thedesired value. A layer 5n thick (in the dry state) is then produced on aphotographic layer base at a casting temperature of 40 C. and a castingrate of 6 meters per minute.

One half of this dyed gelatine layer is covered with a gelatine interlay2,14 thick; in addition to the wetting agent and the hardener this layercontains no further additives. The other half of the dyed gelatine layeris covered with a gelatine interlay 2n thick, which contains the sameadditives and also in addition 16.7% (referred to gelatine) of thecompound of the Formula I.

Both interlays are then covered in the known manner with a silver halideemulsion to produce a layer 5 thick in the dry state. The emulsioncontains 7% of gelatine and 34 g. of silver per kg.

Both materials are exposed to incandescent light under a grey stepwedge, developed in a bath containing l-methylamine-4-hydroxybenzenesulphate and hydroquinone to the same silver density and freed fromsilver halide in a bath containing sodium thiosulphate. After anintermediate rinsing in Water, the materials are treated for 8 minutesat 20 C. in a dye bleaching bath of the following composition:

Water ml 1000 Thiourea g 50 Sulfamic acid g 50 Dimethylpyrazine, 1% ml 4The residual silver and residual silver salts are washed out in theknown manner.

When the image density in the unexposed areas and in the areas ofmaximum exposure is measured behind red filters, the following valuesare obtained:

Maximum Minimum density density Experiment with nitro compound 1. 91 1.4 Experiment without nitro compound 1. 88 0.1

These values show clearly that the presence of the nitro compound in theinterlay results in a substantial reduction of the dye bleaching.

Example 3 12' 12 ml. of methanol containing 1.25 g. of Compound XXIX,and 1 ml. of hardener solution (plate A).

3.5 ml. of the same solution but without the compound of the FormulaXXIX is poured over the other glass plate (plate B).

After drying, each plate is covered with a mixture of 1.65 ml. of 6%gelatine, 1 ml. of hardener and 0.29 ml. of a 1% aqueous solution of thedye of the formula son: on,

/N=N I l Nn-o 0 s o 0 03K OCH:

om sou:

0cm sour and 2.1 ml. of water.

A strip of each of these plates A and B is exposed under a grey stepwedge for 3 seconds with 500 lux and then treated for (a) 10 minutes inthe developer G. p-Methylaminophenol sulphate 1 Sodium sulphite,anhydrous 20 Hydroquinone 4 Sodium carbonate, anhydrous 10 Potassiumbromide 2 Water to 1000 ml.

(b) 2 minutes washing (c) 6 minutes in the stop-fixing bath sodiumthiosulphate cryst. g 200 Sodium sulphite, anhydrous g 15 Sodium acetate(3H O) g 25 Glacial acetic acid ml 13 Water to make 1 litre.

(d) 8 minutes rinsing in water (e) 20 minutes in a dye bleaching bathPotassium iodide g 20 Sodium hypophosphite, cryst. g 0.2 Sulphuric acid,96% ml 55 Water ml 1945 Ethanolic solution containing 0.3 g. of 2,3-

dimethyl-6-aminoquinoxaline in 50 ml. of ethanol ml 30 (f) 4 minutesrinsing in water (g) 8 minutes in a silver bleaching bath G. Potassiumferricyanide '50 Potassium bromide l5 Disodium phosphate 10 Monosodiumphosphate Water to make 1 litre. (h) 6 minutes rinsing in water (i) 6minutes in a fixing bath (same composition as the stop-fixing bath), (j)10 minutes rinsing in water.

The strip B reveals a yellow dye wedge, whereas strip A is of a uniformyellow color. When the dye density in the absorption maximum of therespective-dye 'inthe two strips is measured in the same area, i.e.where maximum exposure occurred, strip A reveals the relative value of1.6 and strip B of 0.26, that is to say the reduced form of the catalystdiffusing from the" silver halide emulsion reaches the dye layer instrip B and produces a bleaching of the dye, whereas in strip A thecompound of the'Formula XXIX which is present causes the reoxidation ofthe reducedcatalystwsozthat it: cannot react at all or only slightly inthe dyed-layer.

When in these experiments the yellow dye of the Formula 12 is replacedby the cyatfdye of the formula a value of 1.29 is obtained for strip Aand a value of 0.6 for strip B.

When less than 1.25 g. of theCompound XXIX is used in plate A, allotherconditions being equal, yellow dye any desired degree of gradation'ofthe plates A and B can be achieved by a suitable choice of theconcentration of Compound XXIX. This method may also be used to obtainthe optimum individual gradations in a multipack material, especially byusing the appropriate quantity of Compound X'XIX in each individuallayer.

\ Example 4 Atranspareti t cellulose'triacetate base is coatedsuccessively with the following layers: 1) Gelatinela'ye'r containingthe dye of the formula Layer 1.5,u thick.s.-;Dye concentration: 0.11g./m. (2) Silver bromide gelatin emulsion, red-sensitive. Layer 1.5g.thick. Concentrations 0.55 g. of silver/m (3) Interlay, containing thecompound of the Formula XXX. Layer 1.5,u thick. Concentration: 0.44 g.of the compound of the Formula )OCX per m (4) Gelatine layer containingthe dye of the formula SOaNa Layer 1.5,u thick. Concentration 0.15 g. ofdye/m9.

For comparison the same multi-layer material is prepared but withoutCompound XXX in layer 3. The two materials are exposed behind a stepwedge and processed for (a) 10 minutes in the developer Gp-Methylarninophenol sulphate 1 Sodium sulphite, anhydrous 20Hydroquinone 4 Sodium carbonate, anhydrous 10 Potassium bromide 2 Madeup with water to 1 litre.

(b) 2 minutes rinsing in water (0) 6 minutes in stop-fixing bath Sodiumthiosulphate, cryst. g.... 200 Sodium sulphite, anhydrous g 15 Sodiumacetate (3H O) g 25 Glacial acetic acid ml 13 Water to make 1 litre.

(d) 8 minutes rinsing in water (e) 20 minutes in dye bleaching bathp-Toluene sulphonic acid Sodium hypophosphite, cryst g 2 Potassiumiodide ..-g 25 Catalyst (2,3-dimethylquinoxaline) mg 50 Water to make 1litre.

(f) 4 minutes rinsing in water (g) 8 minutes in silver bleaching bathPotassium ferricyanide 50 Potassium bromide 15 Disodium phosphate 10Monosodium phosphate 14 Water to make 1 litre. (h) 6 minutes rinsing inwater (i) 4 minutes in fixing bath (prepared as for stopfixing bath) (j)8 minutes rinsing in water.

The following table shows the analytical dye densities depending on theexposure. It is clearly seen that the compound of the Formula XXXprevents the difiusion of the reduced catalyst in the magenta layer buthas no influence on the speed of the silver halide layer.

Density of the steps in the magenta layer in percent Without the suh-With the substance of Formula stance of Formula XXX in the XXX in theinterlnyer interlayer where A is benzene, naphthalene, diphenyl,pyridine,

quinoline or phenylpyrazolone, B is a diffusion-inhibiting group boundto group A directly or through a -NR-CO,

--CONR, O or NR- bridge where R is hydrogen or an alkyl group having atmost 5 carbon atoms, B comprising a linear or branched, saturated orunsaturated,

substituted or unsubstituted hydrocarbon radical which when substitutedcontains (a) nitrogen, oxygen or nitrogen and oxygen atoms,

as substituents or chain members,

(a) carboxylic nuclei,

(c) carboxylic nuclei and nitrogen, oxygen or nitrogen and oxygen assubstituents or chain members, said diffusion-inhibiting groupcontaining at least 8 members, D and E each is an acid group whichconfers water solubility, m, n, p, and r each is 1 or 2 and q is 1, 2 or3.

2. A photographic material according to claim 1 in whichdiifusion-inhibiting group B contains from 8 to 25 carbon atoms and isselected from alkyl, alkylamino, alkanoyl,phenylcarbamoylalkylenecarbonyl, alkylphenoxymethylene,alkanoylaminophenylcarbamoylanilide, alkanoylphenylcarbamoyl,phenoxypolyethyleneoxyalkylene, alkylpyrazolone, N-alkylatedaminophenyl,aliphatic carbocyclic having up to 19 carbon atoms,benzamidodiphenylamino optionally substituted in the diphenyl moiety bylower alkoxy, phenylcarbamoyloxy-polyethylenoxycarbonyl andanilinoalkylene, D and E each is an acid group which confers watersolubility, m, n, p and r each is 1 or 3. A photographic materialaccording to claim 2 in which D and E each is a sulfonic or carboxylicacid group.

4. A photographic material according to claim 1 in which A is a benzeneor naphthalene radical.

5. A photographic material according to claim 2 in which the bridge is Oor NR-CO-.

6. A photographic material according to claim 3 in which A is a benzenering, D and E each is a sulfonic acid group or a carboxylic acid group,B is an alkyl radical having from 8 to 18 carbon atoms linked to group Athrough the NHCO bridge or a sulfonated benzene radical substituted byan alkylamino group wherein the alkyl moiety contains from 8 to 18carbon atoms, said benzene radical being linked to group A through theCONH- bridge, m is 1, n, p, q and r each is 1 or 2.

7. A photographic material as claimed in claim 1 containing a nitrocompound of the formula ('lJHa NH-CO-G OZN in which G represents aresidue of the formula OxHZXil r C I-I COOH, in which x is a digit offrom 11 to 17 and y is a digit of from 14 to 20, and D represents asulfonic or carboxylic acid group.

'8. A photographic material'as claimed in. claim 1 containing a nitrocompound of the formula 1' SOzH 9. A photographic material as claimed inclaim 1 containing a nitro compound of the formula (XXIX) OCH:

NH-CO-CuNu OzN SOaH

10. A photographic material as claimed in claim containing a nitrocompound of the formula (XXX) H018 11. A photographic material asclaimed inclaim 1 of the formula XXXI H1 uHu 'smH References CitedUNITED STATES PATENTS 3,457,074 7/1969 Wilson et a1. 96-73 NORMAN G.TORCHIN P'rimary Examiner R. L. SCHILLING, Assistant Examiner US. Cl.X.R. 9699, 53

V UNITED STATES PATENT OFFICE M CERTIFICATE OF CORRECTION Patent No.3,782,948 Dated Januarv l, 1914 lnventofls) 'ALFRED FROELICH ET AL It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 14, claim 1, line 60, delete "on" and substitute one T 1 V TColumn 3 1%,)claim 1, line 5, delete "(a)" and, substitute T T b T PSigned fidsea led thi luth day ofFMay (SEAL) Attest:

EDWARD M.FLETGEER,JR. T M T c. MARSHALL DA I Attesting OfficerComissioneref Patents J

